Display device with touch sensor, potential control method, and program

1. A display device with a touch sensor, comprising: a display pixel electrode; a thin-film transistor circuit connected to the display pixel electrode; a common electrode that is opposed to the display pixel electrodes; a display function layer configured to display an image; a display control circuit configured to apply a display voltage between the display pixel electrode and the common electrode based on an image signal, and configured to control an image display of the display function layer, and configured to apply a touch sensor drive signal to the common electrode; a touch detection electrode that is opposed to the common electrode and that is configured to form a capacitance between the touch detection electrode and the common electrode; a gate buffer configured to select between a first wiring and a second wiring to connect the selected wiring to a gate of the thin-film transistor circuit; and a switch arranged between the gate buffer and the second wiring and configured to set the gate buffer to a floating state during application of the touch sensor drive signal, wherein during a vertical blanking period or a horizontal blanking period, a potential of the gate is set to a floating state, in which the gate and the gate buffer are in an electrically open state, in which the switch is set to be opened such that the gate buffer is in the floating state, wherein the display device comprises a plurality of the display pixel electrodes and a plurality of the thin-film transistor circuits, and each of the thin-film transistor circuits is connected to one of the display pixel electrodes on a one-to-one basis, and wherein the display device comprises a plurality of the gate buffers and a plurality of the switches, wherein each of the gate buffers is configured to connect the selected wiring to each of the gates of corresponding thin-film transistor circuits among the plurality of thin-film transistor circuits, and each of the switches is provided for one of the gate buffers on a one-to-one basis.

2. The display device with a touch sensor according to claim 1 , wherein a display drive voltage having a fixed voltage amplitude, applied to the common electrode by the display control circuit is utilized as the touch sensor drive signal, and wherein a potential of the gate is set to the floating state, in which the gate and the gate buffer are in an electrically open state, so as to become a potential subjected to coupling by the touch sensor drive signal.

3. The display device with a touch sensor according to claim 1 , wherein the first wiring supplies a first voltage to the gate buffer, and the second wiring supplies a second voltage to the gate buffer.

4. The display device with a touch sensor according to claim 1 wherein a display drive voltage having a fixed voltage amplitude, applied to the common electrode by the display control circuit is utilized as the touch sensor drive signal, and wherein a predetermined voltage is applied through the gate buffer to the gate of the thin-film transistor circuit.

5. The display device with a touch sensor according to claim 4 , wherein the gate is set to an on state when a first gate voltage is applied to the gate through the gate buffer, wherein the gate is set to an off state when a second gate voltage is applied to the gate through the gate buffer, and wherein during the application of the touch sensor drive signal the gate is set to the floating state, when the switch is opened and the gate is electrically disconnected from the gate buffer.

6. A display device with a touch sensor, comprising: a display pixel electrode; a thin-film transistor circuit connected to the display pixel electrode; a common electrode that is opposed to the display pixel electrodes; a display function layer configured to display an image; a display control circuit configured to apply a display voltage between the display pixel electrode and the common electrode based on an image signal, and configured to control an image display of the display function layer, and configured to apply a touch sensor drive signal to the common electrode; a touch detection electrode that is opposed to the common electrode and that is configured to form a capacitance between the touch detection electrode and the common electrode; a gate buffer configured to select between a first wiring and a second wiring to connect the selected wiring to a gate of the thin-film transistor circuit; and a switch arranged between the gate buffer and the second wiring and configured to set the gate buffer to a floating state during application of the touch sensor drive signal, wherein during a vertical blanking period or a horizontal blanking period, a potential of the gate is set to a floating state, in which the gate and the gate buffer are in an electrically open state, in which the switch is set to be opened such that the gate buffer is in the floating state.